
<template>
  <div id="app">
    <!-- 需求1: 把默认数据显示到表格上 -->
    <!-- 需求2: 注意资产超过100的, 都用红色字体标记出来 -->
    <!-- - 需求1: 实现表单数据新增进表格功能
         - 需求2: 判断用户输入是否为空给提示
      -->
    <!-- 
        - 需求1: 点击删除的a标签, 删除数据
        - 需求2: 删除没数据了要提示暂无数据的tfoot
       -->
    <!-- 
        目标: 复制上个案例, 在此基础上, 把表格里的时间用过滤器+moment模块, 格式化成YYYY-MM-DD 格式
    -->
    <!-- 目标: 基于之前的案例, 完成总价和均价的计算效果 -->
    <!-- 目标: 侦听list变化, 同步到浏览器本地 -->
    <div class="container">
      <!-- 顶部框模块 -->
      <div class="form-group">
        <div class="input-group">
          <h4>品牌管理</h4>
        </div>
      </div>

      <!-- 数据表格 -->
      <table class="table table-bordered table-hover mt-2">
        <thead>
          <tr>
            <th>编号</th>
            <th>资产名称</th>
            <th>价格</th>
            <th>创建时间</th>
            <th>操作</th>
          </tr>
        </thead>
        <tbody>
          <tr v-for="val in list" :key="val.id">
            <td>{{ val.id }}</td>
            <td>{{ val.name }}</td>

            <!-- 如果价格超过100，就有red这个类 -->
            <td :class="{ red: val.price > 100 }">{{ val.price }}</td>
            <td>{{ val.time | formatDate }}</td>
            <td><a href="#" @click.prevent="delBtn(val.id)">删除</a></td>
          </tr>
          <tr style="background-color: #eee">
            <td>统计:</td>
            <td colspan="2">总价钱为: {{ allPrice }}</td>
            <td colspan="2">平均价: {{ svgPrice }}</td>
          </tr>
        </tbody>

        <tfoot v-if="!this.list.length">
          <tr>
            <td colspan="5" style="text-align: center">暂无数据</td>
          </tr>
        </tfoot>
      </table>

      <!-- 添加资产 -->
      <form class="form-inline">
        <div class="form-group">
          <div class="input-group">
            <input
              type="text"
              class="form-control"
              placeholder="资产名称"
              v-model.trim="name"
            />
          </div>
        </div>
        &nbsp;&nbsp;&nbsp;&nbsp;
        <div class="form-group">
          <div class="input-group">
            <input
              type="text"
              class="form-control"
              placeholder="价格"
              v-model.number="price"
            />
          </div>
        </div>
        &nbsp;&nbsp;&nbsp;&nbsp;
        <!-- 阻止表单提交 -->
        <button class="btn btn-primary" @click.prevent="addBtn">
          添加资产
        </button>
      </form>
    </div>
  </div>
</template>

<script>
// 2. 定义过滤器, 编写内部代码
import moment from "moment";

export default {
  data() {
    return {
      name: "", // 名称
      price: 0, // 价格

      /*  list: [
        { id: 100, name: "外套", price: 199, time: new Date("2010-08-12") },
        { id: 101, name: "裤子", price: 34, time: new Date("2013-09-01") },
        { id: 102, name: "鞋", price: 25.4, time: new Date("2018-11-22") },
        { id: 103, name: "头发", price: 19900, time: new Date("2020-12-12") },
      ], */
      // 3. 本地取出缓存list
      list: JSON.parse(localStorage.getItem("pList")) || [
        { id: 100, name: "外套", price: 199, time: new Date("2010-08-12") },
        { id: 101, name: "裤子", price: 34, time: new Date("2013-09-01") },
        { id: 102, name: "鞋", price: 25.4, time: new Date("2018-11-22") },
        { id: 103, name: "头发", price: 19900, time: new Date("2020-12-12") },
      ],
    };
  },
  methods: {
    addBtn() {
      if (!this.name) return alert("请输入正确名字");
      this.list.push({
        id: this.list.length ? this.list[this.list.length - 1].id + 1 : 1,
        name: this.name,
        price: this.price,
        time: new Date(),
      });
      this.name = "";
      this.price = "";
    },
    delBtn(index) {
      console.log(index);
      /* this.list.splice(
        this.list.findIndex((item) => item.id === index),
        1
      ); */
      this.list = this.list.filter((item) => item.id != index);
    },
  },
  filters: {
    formatDate: (val) => moment(val).format("YYYY-MM-DD HH:MM:SS"),
  },
  computed: {
    //计算总价
    allPrice() {
      let sum = 0;
      this.list.forEach((item) => {
        sum += item.price;
      });
      return sum;
      // return this.list.reduce((sum, obj) => (sum += obj.price), 0);
    },
    svgPrice() {
      // return 10;
      return (this.allPrice / this.list.length).toFixed(2);
    },
  },
  watch: {
    list: {
      handler() {
        // 2. 存入本地
        localStorage.setItem("pList", JSON.stringify(this.list));
      },
      deep: true,
    },
  },
};
</script>

<style >
.red {
  color: red;
}
</style>